LIGHT. 95 



process taking place during germination,) and that this 

 evolution is greatest where the destruction of oxygen 

 is so too, and that the more the plant is exposed to 

 its influence, the greater is the heat ; for, says Vrolick, 

 in oxygen we see a considerable increase of size, a de- 

 velopment full of vigour, a natural colour, a very high 

 temperature, in fine, everything that announces a vivi- 

 fying and exciting action in the whole functions ; whilst 

 in nitrogen, on the other hand, cessation of movement, 

 stagnation of all vital action, arrested growth, colour 

 lost, production of heat interrupted, and complete disso- 

 lution to be feared. 



91. M. Dunal, although agreeing that the absorp- 

 tion of oxygen and its combination with carbon, are the 

 causes of this generation of heat, supposes that this is 

 brought about independent of respiration, and that the 

 process is one of pure nutrition; that a formation of 

 saccharine matter takes place in the nectary and petals, 

 and that this is conveyed to the anthers and ovules as 

 a nourishment for them, and that it is in the formation 

 of this saccharine matter by the plant that the heat is 

 evolved. 



92. Light. In regard to the disengagement of light 

 by plants, a few observations only can be here stated, as 

 aU circumstances connected with it are clothed in much 

 doubt. 



9-3. The daughter of Linnaeus observed a sudden 

 gleam of light come from the flowers of Tropaeleum 

 Majus, which fact was afterwards substantiated by Lin- 

 naeus himself, and likewise by his son ; Crome, on the 

 31st July, 1808, between 10 and 11 P.M., noticed a 

 luminous appearance proceeding from the spur of the 

 same flower, and which, when touched by the finger, 

 became stronger and followed its motion. Zavadski 

 saw the same thing, not only from this plant, but 

 from others also; and several observers might be 

 added who have placed upon record statements which 

 go to prove that sudden glances of light have been seen 



